The formation of an epidermoid carcinoma in nonhealing scar tissue, a Marjolin's ulcer, is a well described neoplasm. These lesions are, however, frequently overlooked and often inadequately treated. This paper reviews six cases of scar-tissue carcinoma. All lesions were secondary to various kinds of burns. Four of the Marjolin's ulcers were well-differentiated squamous cell carcinomas. One was a moderately differentiated squamous cell carcinoma, and one was a malignant melanoma. The average age at presentation was 59 years, and the mean interval from time of burn injury to appearance of neoplasm was 36.8 years. The lesions varied in anatomic location and involved the upper extremities, lower extremities, and scalp. In addition to the case studies, this paper reviews the literature and provides a logical treatment plan for a patient with a Marjolin's ulcer. Because these lesions can be very aggressive, a well thought-out treatment plan is necessary to optimize care and assure patient survival.